1. Technical Field
The present disclosure relates to molding technology, particularly to an apparatus and a method for molding optical elements, such as wafer-level lenses.
2. Description of Related Art
Wafer level camera technology is designed to advance the integration of miniaturized cameras into cellular phones, PCs, security cameras and other portable electronic devices. To manufacture cameras at the wafer level, thousands of lenses are built simultaneously on a wafer, and a plurality of wafers are aligned and bonded together. The bonded wafers are diced into individual integrated optical elements that can be mounted onto a packaged image sensor. This technology drastically reduces the size and cost of camera modules.
A typical mold for molding lenses at the wafer level includes an upper mold core and a lower mold core. The upper mold core has an upper molding surface. The lower mold core has a lower molding surface corresponding to the upper molding surface. The upper molding surface and the lower molding surface cooperatively define a molding cavity to mold wafer-level lenses. The upper mold core and the lower mold core must be precisely aligned with each other to ensure good optical properties of the lenses. However, it is difficult to precisely align the upper mold and the lower mold.
What is needed, therefore, is an apparatus and a method for manufacturing miniature optical elements which can overcome the above-described problem.